A Guide to Ensuring Wireless LAN Reliability - Motorola Solutions

WHITE PAPERA Guide to EnsuringWireless LAN Reliability

IntroductionIf a quick Google search is any indication, then security and cost are the topconcerns regarding wireless LAN purchases, and reliability is an afterthought.Searching “Wireless network” and “security” garners 4,740,000 hits. “Wirelessnetwork” and “cost” – 4,150,000 hits. But Googling “wireless network” and“reliability” results in a comparatively paltry 931,000 hits – approximately 80%fewer.! This would seem to indicate that while IT managers are consideringWireless LANs as a feasible alternative networking option, unfortunately, manydon’t sesem to be considering the reliability of this networkYes, network security is extremely important, as evidenced by myriad headlinesabout hackers stealing credit card numbers. And yes, of course the priceof network equipment should be of vital concern, especially in the currenteconomy. But nothing is more important than making sure the network actuallyruns! And so when a company is considering a new wireless network, the firstquestion should be, “Is it reliable?” and the second question should be, “Howcan I make sure it’s ALWAYS reliable?”Every professional IT manager is familiar with the goal of “five nines,” referringto a network that is up, running and available 99.999% of the time. It’s a loftybut worthwhile goal, as the closer you come to meeting it, the more money youwill save. Network downtime is not just frustrating; it’s quantifiably expensive.A recent study of 80 large corporations, from Infonetics Research, showed thatcompanies experience an average of 501 hours of network downtime annually,including both outages and service degradations. The average cost of thisdowntime equaled a whopping 3.6 percent of a company’s annual revenue, thestudy found. And these days, when IT managers talk about network downtime,they’re often referring to a company’s wireless LANAs few as ten years ago, IT managers relegated their network uptime concernsto the wired network. Wireless LANs were viewed largely as ancillaryluxuries, and if the wireless network went awry, well, so be it. With employeeproductivity tightly tied to employee mobility, most companies rely on theirwireless networks for core business operations. Today’s network users considerthem less a luxury and more a necessity.It should be noted that in a wireless world, network downtime affects not onlythe office, but also all the mobile devices connected to the network – from thewireless scanners on the manufacturing floor to the networked infusion pumpsin a hospital’s emergency room to that dual-mode smartphone that is becomingkey to user productivity.In the nascent days of Wi-Fi, a corporate wireless LAN comprised a series ofautonomous access points, scattered throughout the office and even branchoffices around the globe. Garnering an effective radio signal was a matter of trialand error, and because there was no central management, the administratorwouldn’t know there was a problem until someone inevitably complained.Today’s Wi-Fi networks, managed from a central switch, can be even morereliable than a wired Ethernet network – but only if IT directors take thenecessary steps to ensure reliability and promise superior quality of service inevery aspect of the network.

Ensuring reliability meansplanning for expected challengesIt should go without saying that a reliable wirelessLAN depends on smart planning and preemptivetroubleshooting on the part of the IT manager – i.e.designing the network based on the specific needsof the company. Implementing a WLAN withoutconducting a thorough site survey, only to find thatit does not reliably serve your employees, makesabout as much sense as purchasing a VolkswagenBug on a whim, only to find that it does not reliablytransport a family of eight. Such an approach createscoverage, bandwidth and other reliability issues.Before investing in any wireless LAN hardware, itbehooves a company to invest in wireless LANplanning software that helps IT managers toplan a new network as they answer the followingquestions:Who will be using the network, and when willthey be using it? Obviously 2,000 employeesrequire a more robust network than 20 employees.But beyond that, it’s important to note whetherthere are certain times of day when a network – oreven a single access point – is likely to experiencea sudden flood of traffic. For example, is there aMonday morning meeting in which 60 employeesand their individual mobile computers squeeze intoa single conference room?What applications will the network serve?For example, will employees be using the networkmainly for wireless e-mail and Internet access, orwill the network also be used for video and voiceapplications? The latter two likely will requiremore access points. Video transfers require morebandwidth than other applications. And wirelessvoice calls are especially unforgiving when itcomes to network glitches such as latency (alag in data transfer time) and jitter (an unplannedfluctuation in signal transmission.)Which workspaces require wireless LANcoverage? Are the company’s wireless needsrelegated to the so-called “carpeted” areas ofthe office, or will employees need the networkin hallways, manufacturing floors, or the outdoorspaces on large campuses? And are there areason the corporate campus that require the companyto restrict network access to certain employees forsecurity reasons?Are there any obstacles that might interferewith Wi-Fi radio signals? Most businesses andbuildings are rife with possible interferences,including:*Microwave ovens: Unfortunately, microwavescan interfere with the 2.4GHZ 802.11b/g Wi-Fisignals. An access point placed too close toa microwave oven could experiencedegradation in performance every time Bobfrom Accounting makes a bag of popcorn.Older cordless phones and Bluetooth devicesalso interfere with wireless LANs,.*Metal: Many types of metal, especially steeland lead, can block Wi-Fi signals or at leastcause multipath interference, in which radiosignals are unintentionally split into multiplepaths. File cabinets, sculptures, benches, largechairs, and steel doors are obvious problems,but IT managers also must be mindful ofhidden obstacles -- such as metal studs inplaster walls, wire mesh in windows, andsteel beams in ceilings -- and place accesspoints accordingly.*Concrete: Concrete floors and walls tend toblock Wi-Fi signals. This is a boon in terms ofblocking signals from neighboring businesses,but a detriment when it comes to blockingsignals from your own network.*Nature: Especially with regard to networksthat span between two buildings, IT managersmust plan for interference from trees, bodiesof water, and other gifts of nature that mostlikely existed before Wi-Fi ever did.*Someone else’s Wi-Fi network: Just asmicrowave signals can interfere with your Wi-Fisignals, so can the Wi-Fi signals fromneighboring networks – especially if they are operating on the same or neighboring channels.Who will be running the network? Willwireless network operations be under the chargeof one or two IT employees in a single location,or will there be network operators in remotelocations who oversee subsidiary wireless LANsof their own?What are the likely security challenges?Obviously, security breaches can lead to networkdowntime, not to mention stolen data. Does thebuilding’s location make it especially susceptible3 WHITE PAPER: A Guide to Ensuring Wireless LAN Reliability

And unlike many competing companies, Motorola’sareas of wireless expertise extendfar beyond Wi-Fi.Motorola’s unique clustering technology allows upto 12 switch controllers to be configured in a singlecluster and distributed across the Enterprise. Theswitch/controllers have the intelligence to operate asa single virtual operation and load balance the accesspoint load across the cluster. This also enables highavailability as the load for any switch/controllerfailure will be immediately assummed by thecluster. Motorola’s zero-port licensing means usersdon’t have to pay for stand-by ports so the cost ofmaintaining a reliable switch/controller operation issignificantly reduced.As companies increase their reliance on wirelesstechnologies the reliability value of Motorolanetworks will be more critical. From planning tomanaging to adjusting to failover to anticipating thefuture, Motorola offers the most reliable wirelessLAN portfolio on the market. Whether a networkis concentrated in a campus or distributed globallyacross theaters, Motorola offers unparalleledmulti-level resiliency. Network downtime is as costlyas throwing money down the drain. Employing aMotorola wireless LAN will help you put that moneyto better use.7 WHITE PAPER: A Guide to Ensuring Wireless LAN Reliability

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